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Video:All About Planet Earth

This video will give you a glimpse into our planet earth. Between information about life forms and facts about geology, there is plenty to learn about planet earth.See Transcript

Transcript:All About Planet Earth

Hello, my name is Edmond Mathe, I'm a Geologist in the department of Earth and Planetary Sciences at the American Museum of Natural History and I'm here for About.com. Today I'm going to tell you about the earth.

Facts About Planet Earth

Welcome to planet earth. Our planet Earth is the third planet from the sun, it's the 5th largest in the solar system and the densest. One year equals 365.25 days in orbit around the sun. The earths circumference at the equator is 24, 900 miles. The earth's land mass is 57 million, 511 thousand, 26 point 002 square miles. Water covers approximately 70.8 percent of the earth's surface. Let's look at some of its Geology.

Changes of Planet Earth

If we were to look inside it's a very dynamic place and it's moving all the time. The earth has a metal core. An iron nickel metal core. The interior of which is solid.And then around that solid inner core, is a liquid outer core that's in conastant motion and in fact gives us the magnetic field that we see at the surface of the planet. Beyond that core is the mantle. The mantle is in motion. Generally, it's almost completely solid. It convects. It moves it flows like putty. The surface is perched on crust, which actually moves in response to the movements of the mantle and that's what gives us what's called plate tectonics. The movement of the large rigid plates on the surface of, the plate tectonics gives us mountain belts, gives us Ocean basins.

Planet Earth's Age

The earth is old. It's about 4.5 billion years old. It formed by the agglomeration of dust and rock particles in the early solar system. The planet has had a very dynamic history. Mountains have grown and eroded away and you seee the vestages of these old features. Around the plamet. Especially around the old parts of continents. Which is parts of Canada, Greenland, South Africa.

Life on Planet Earth

But, why does life exist here and nowhere else in the solar system? It's a very special planet. We believe that life existed here 3.8 Billion years ago. Not only is it a place where life begand but is also a place where life evolved. It's in other words in the habitable zone. It's not too close to the sun that water, that liquid water can't exist, as on Venus for example. OPn the other hand Mars is too far from the Sun and the surface of Mars is frozen. But, eath, in a sense, kis the Goldilocks planet. It's not too close and it's not too far. It's just the right distance from the sun to support life.

Planet Earth's Protective Atmosphere

It has a protective atmosphere. The atmosphere houses greenhouse gases and those greenhouse gases, even though they're a problem today, through earth's hisotyr they';ve kept the planet warm enough so that water has actually existed in its liquid state as opposed to either being frozen or near it being too hot.

Thanks for watching and to learn more, visit us on the web at About.com.

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